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.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
.\"                               1993 Michael Haardt;
.\"                          1993,1995 Ian Jackson.
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.\" Modified Sat Jul 24 00:35:52 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified Thu Jun  4 12:21:13 1998 by Andries Brouwer <aeb@cwi.nl>
.\"
.TH RENAME 2 "4 June 1998" "Linux 2.0" "Linux Programmer's Manual"
.SH NAME
rename \- change the name or location of a file
.SH SYNOPSIS
.B #include <stdio.h>
.sp
.BI "int rename(const char *" oldpath ", const char *" newpath );
.SH DESCRIPTION
.B rename
renames a file, moving it between directories if required.

Any other hard links to the file (as created using
.BR link (2))
are unaffected.

If
.I newpath
already exists it will be atomically replaced (subject to
a few conditions - see ERRORS below), so that there is
no point at which another process attempting to access
.I newpath
will find it missing.

If
.I newpath
exists but the operation fails for some reason
.B rename
guarantees to leave an instance of
.I newpath
in place.

However, when overwriting there will probably be a window in which
both
.I oldpath
and
.I newpath
refer to the file being renamed.

If
.I oldpath
refers to a symbolic link the link is renamed; if
.I newpath
refers to a symbolic link the link will be overwritten.
.SH "RETURN VALUE"
On success, zero is returned.  On error, \-1 is returned, and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EISDIR
.I newpath
is an existing directory, but
.I oldpath
is not a directory.
.TP
.B EXDEV
.IR oldpath " and " newpath
are not on the same filesystem.
.TP
.BR ENOTEMPTY " or " EEXIST
.IR newpath
is a non-empty directory, i.e., contains entries other than "." and "..".
.TP
.B EBUSY
The rename fails because
.IR oldpath " or " newpath
is a directory that is in use by some process (perhaps as
current working directory, or as root directory, or because
it was open for reading) or is in use by the system
(for example as mount point), while the system considers
this an error.
(Note that there is no requirement to return EBUSY in such
cases - there is nothing wrong with doing the rename anyway -
but it is allowed to return EBUSY if the system cannot otherwise
handle such situations.)
.TP
.B EINVAL
The new pathname contained a path prefix of the old, or, more generally,
an attempt was made to make a directory a subdirectory of itself.
.TP
.B EMLINK
.I oldpath
already has the maximum number of links to it, or
it was a directory and the directory containing
.I newpath
has the maximum number of links.
.TP
.B ENOTDIR
A component used as a directory in
.IR oldpath " or " newpath
is not, in fact, a directory.
Or,
.I oldpath
is a directory, and
.I newpath
exists but is not a directory.
.TP
.B EFAULT
.IR oldpath " or " newpath " points outside your accessible address space."
.TP
.B EACCES
Write access to the directory containing
.IR oldpath " or " newpath
is not allowed for the process's effective uid, or one of the
directories in
.IR oldpath " or " newpath
did not allow search (execute) permission, or
.I oldpath
was a directory and did not allow write permission (needed to update
the
.B ..
entry).
.TP
.BR EPERM " or " EACCES
The directory containing
.I oldpath
has the sticky bit set and the process's effective uid is neither that of root
nor the uid of the file to be deleted nor that of the directory containing it,
or
.I newpath
is an existing file and the directory containing it has the sticky bit set
and the process's effective uid is neither that of root nor the uid of the
file to be replaced nor that of the directory containing it,
or the filesystem containing
.IR pathname
does not support renaming of the type requested.
.TP
.B ENAMETOOLONG
.IR oldpath " or " newpath " was too long."
.TP
.B ENOENT
A directory component in
.I oldpath " or " newpath
does not exist or is a dangling symbolic link.
.TP
.B ENOMEM
Insufficient kernel memory was available.
.TP
.B EROFS
The file is on a read-only filesystem.
.TP
.B ELOOP
Too many symbolic links were encountered in resolving
.IR oldpath " or " newpath .
.TP
.B ENOSPC
The device containing the file has no room for the new directory
entry.
.SH "CONFORMING TO"
POSIX, 4.3BSD, ANSI C
.SH BUGS
On NFS filesystems, you can not assume that if the operation
failed the file was not renamed.  If the server does the rename operation
and then crashes, the retransmitted RPC which will be processed when the
server is up again causes a failure.  The application is expected to
deal with this.  See
.BR link (2)
for a similar problem.
.SH "SEE ALSO"
.BR link (2),
.BR unlink (2),
.BR symlink (2),
.BR mv (1)